Preparation of alkene phosphonous acids



BEST AVAILABLE COPY United States Patent Ofifice Patented Nov. 2, 1954 9cm asst-m This invention relates to the preparation of organic phosphorus-bearing compounds, and more particularly to a new recess for preggrlg alkene phosphonous acids.

In e followin ption the term alkene phosphonous acids refer to the structure:

n n n o a wherein R and R mrggbe a hydrogen or an alltyl cup. This is to be preferred representation these acids, althoughamtmberofwritcme. g.,.\rbuzov conr r aa fi a'zirs a on" its mpg n illlla-all un a published by ilcy & Sou, page 144).

and of a hydr phosphonous acids constitute preparation of 1 pounds suitable as fol compositions, foam agents.

Itisaprimaryobiectofthepresenthtventiontoprovide a process for preparing alkene p nous acids by a heretofore unknown reaction of an o efin, phosphorus trichltiride and. aofntic dc, resetting ingle orma. 0110 an organic t to centammgtwo osphorus atoms, three oxygen atoms and a saturated hydrocarbon group, this intermediate tarpon hydrolysis and ehydration providing good yields of kene phosphonous acid.

Another obyect of the result is to rovidc valuable surface-active derivatives of alkene phosp onous ac s by reacting these acids with albiene and polyalkyicne glycols.

Still another object of the invention is to provide valuable rtialcsters derived from the in d by the aforementioned reaction of an oieflp. phosgleiorus trichlorideand aceticanhydride, aaidpamal esters alira ]secured by esterifying the intermediates with o s. Other obilectsi of this invention will appear from the ere description t k n accordance w preeen discovery, ens phosphonous acids are obtxed by an oletia, phosphorus trichloride and acetic anhy do, and b subsequently hydrolybz itnge and dehydrating the result ng reaction roduct m to be restricted by theoretical us acid radlcal, alkene materials for the lame number of surface-naive comingredients for a greatvariety of use- Whi my inventionisnot considerations, the able mechanism of the exothermic reaction between e oleiiru. qahorus trichloride and acetic anhydride is the format on of organic phosphonrsbearing intermediates which contain two phosphorus atoms and three oxygen atoms and will be designated hereinafter underthe namcofalkane bosphorites. These intermediates, in which the hydrocarion portion is saturated, are converted b hydrolysis and dehydration to alkene phosphonous a ds.

The formation of intermediates can be represented by the equation: a

W the presence of a hydrophobic all enyl group e. 3., detergents, wetting agents and wherein R and R may be hydrogen or alkyl radicals.

Hydrolysis and dehydration converts the alkane phosphorite intermediate to aikene phosphonous acid and phosphorous acid in accordanq: with the equation:

in carrying out the process of my invention the followin; general will be employed. The olefin, acetic anhy do and phosphorus trrchlcride are introduoed into a reaction flask to form a homogeneous liquid mixture which is stirred at a temperature ranging from about 0' to about 150' C., and preferably from about room temperature to about 80' C., for a period of time which may range from about 8 to about 12 hours. A crystalline precipitate of alkane phosphorite intermediate is formed, and the mixture is allowed to stand in order to complete the reaction, which may require as much as 70 hours, depending on the molar ratio of the initial reactants and the reaction temperature. There after, the mixture containing the precipitate is treated th an excess of water at a temperature from about to about 150' C., whereupon a vigorous reaction takes place. On extracting with ether and evaporating, alltene phosphonous acids formed by this hydrolyzing and dehydrating treatment are recovered in good yields of the order of to by weight based on the initial olefin.

acids are insoluble in water but dissolve in dilute caustic solutions. The acetyl chloride present in the mixture together with the intermediate is converted by hydrolysis to acetic acid, the presence of which, as well as that of the water-soluble phosphorous acid being formed, aid in catalyzing the hydroliylsli of the intermediate to alkene phosphonous acids. reactants for the aforedescribed formation of alkane phosphgrite ingermeidiatc; are engpio m proportions ranging om a out to mols .phzphorus tn'chloride and from about l to 4 mols of acetic anhydride to each mol of the olefin.

The time required for the formation of the desired alkane phosphor-rte is a function of temperature: the higher is the temperature the shorter is the time of reaction, and conversely.

The olefinic materials which may be employed for the production of alkene hosphonous acids by the process described herelnabovg'inclndes straight-chain olcfins, isocyclo-olefins, pol rized olefins and arylnted eflns, such as styrene. letins containing from 8 to 20 in] n atomsdinritlheelrgolecgjenare referredi and, i2 part at, those e y po erizrng propy one an containin from 9 to 18 carbon atoms.

Wh e the relative proportions of the reactants for the production of alkane phosphorite intermediates may be varied within the limits bereinabove described, the best yields (of the order of $0 to 70% based on the weight of the initial olefin) of alkene phosphonous acids will be secured by employing a mixture of 1 mol of olefin to 2 mols of phosphorus trichloride and 3 mols of acetic anhydride. When acetic anhydride and phosphorus trichloride are employed in greater amounts, the 'elds do increase but the over-all cost of the process also increases.

While the invention in its broad aspect resides in reacting an olefin, phosphorus trichloridc and acetic anhydride in order to form an alkane phosphorite intermediate convertlble by hydrolysis and diicilydration to alkene phosphonous acids, a preferred to ification of my process contemplates reacting the above-named three reactants while simultaneously bubbling through their mixture a current of oxy en or air. This modified procedure permits of substant ally reducing the time otherwise necessary for the formation of an intermediate convertible BEST AVAILABLE COPY by hydrolysis and dehydration to alkene phosphonous acids. The intermediate produced in this case, however, is not an alkane phosphonte containing 3 oxygen atoms, but an alltane phosphorate con four oxy en atoms,

nlkane phoslphorate intermediate also produce faod yields of alkene p osphonous acids in accordance w the following equation:

it a H\ n' As can be seen from this uation, phosphoric acid is formed together with alkene p osphonous aci but again the presence of hosphoric acid and of see acid resulting from the ydrolysis of acetyl chloride exercises a favorable catalytic effect on the reaction of formation of alltene phmhonous acids.

In this at cation of the process of my invention a homogeneous liquid mixture of olefin, acetic anhydride and phosphorous trichloride is placed into a reaction flask and a current of pure oxygen or air is bubbled through at a tem ture which may range from about to about 150 C., but preferably from about room temperature to about 80' C. precipitate of ethane phosphorate is formed. l on continuing to bubb e the oxy it through the reaction mixture, thimreeipitate turns yellow in color and finally dissolves. en the is completed, the alkaue phosphorate intermediate can be repreci itated with the aid of petroleum ether. Upon treating is phosphorate with water at a temperature g from 50 to 150' C., alltene phosphonous acids insolu la in water but dissol ing in aqueous solutions of caustic are readily recovered by extracting with ether and evaporating. oxygen over the molar amount of oleiln is employed order to secure the yield of alkane p horate comparable to those of alkahe p horlte o ble without the introduction of oxygen or In view of the strongly exothermic character of the e application of oxygen in my roeess requires more ave out numerous tests to alkene toduce phosphonous acids in accordance with the aforedescribed lnvcnilol'i. The analyses of the alkane pho s phonous acids and of the corresponding alkanefihospho tea and phosphoratcs confirm the nature of 6 products defined in the equations. A number of ntative test runs of preparing alkene phospbonous ac ds and their correspondlngsinicdtrgcdilm are given below in Examples 1, 2, 3,

The intermediate allrane phosphorates and phosphorites are hlghl hygroscopic solids, insoluble in petroleum other an benzene. in all instances the display low bromine numbers of the order of 0.2, in catln a complctc saturation of their hydrocarbon portion. a color of these intermediates ranges from colorless throu h orange to dark brown. depending on tlaxarticuiar olefin involved, the duration of the reaction on whether or not oxygen has been employed. The analyses of these is found to be intermediates indicate an absence of peroxides. Chlorine present merely as an impurity of the order of l to 5% based on the weight of the solid intermediate. Elemental analyses invariably show the presence of two atoms of phosphorus per molecule of the intermediate. The oxygen content determined by sutraction shows the presence of three oxygen atoms in the case of alkane phosphorite and four oxygen atoms in the ease of alitane phosphorate. Furthennore, elemental analyses of ester derivatives of alkane phosphorates and alkane phosphorites, obtained by esterifying these intermediates with aliphatic alcohols, such as'ethyl or butyl alcohol, likewise establish the presence of two phosphorus atoms in each molecule of .the ester derivative. .Although the exact bonding of the alkoxygroups to the phosphorus atoms of these partial esters is not definitely established, i. c. whether one aikoxy group is attached to each phosphorus atom or two alkoxy groups are attached but to one phosphorus atom as in E H O a-i-d-r-ou wherein R is an alkyl group and R the hydrocarbon residue of the alcohol, they can be generally designated as di {1 alkanc phosphonite phosphates and dialkyl alkane p osphonite phosphites, depending on their being derived from alkane pho horates or alkene phosphorites, respectively. The term r shosphonite as employed herein refers to an ester of phosphonous acid.

On the other hand, the acid products obtained by hydrolysis and dehydration of the reaction product mixtures containing alltane phosphorites and alkane phoshorates, as the case may be, invariably display a high romine number of the order of 50, characteristic of unsaturation. These acids'are syrupy iitffiiids stable to the action of water, which fact indicates e rcscncc of a 0-? and not O-O-P linkage. Repeated tttrations of these acidsindicated that they are monobasic. Additionally in-ordcr to double-check the true nature of these alitene pho honous acids, infrared spectral analysis tests were carri out," the results of which discount a possibility of the rcsence of alkene hosphonic rather than alltene phosp onous acids. A efintte absorption is noted in the spectrograrns at about 10.2 mu. is peak is a proof that an alitene structure, i. e., a carbon-to-carbon double bond, is resent. The results of infrared spectral analysis agree with those of the elemental analysis and thus leave not doubt as to the nature of the alltene phosphonous acids obtained upon hydrolyzing and dehydratin alkane' phosphorite and alkane phosphorate intenrtedia The following specific examples are inciludield to illustrate the operation of my invention in more eta Example 1.1-?" oration of n-decene phosphonous acid by way) of a one phosphorite (without introducing oxygen A mixture of 274 g. (2 mols) of hosphorus trichloride, 306 g. (3 mols) of acetic anhydri e and g. 1 mol) of n-decene-I is heated to 35 C. and stirred at that tcmperature for about 16 hours. Thereupon the reaction mixture is left to stand at room temperature for '72. hours. At the expiration of this period it is poured into 1 liter of cold water with continuous stirring and then heated on a steam plate for about one hour. On cooling the mixture, it is extracted with ethyl ether, and the ether extract is washed with dilute sodium hydroxide to remove the n-decene ghosphonous acid as the sodium salt, the aqueous portion i gg thereafter extracted .with ethyl ether to remove unreac n-decene-l. The aqueous portion is acidified, extracted with ethyl ether, and the ether fraction washed with water, dried and evaporated to yield 103.3 g. of n-decene phosphonous acid. The clomental analysis of this acid gives a phosphorus value of 15.15 by we t, which figure is in good agreement with the cal a value of phosphorus content c ual to 15.2%. The results of the infrared anillysis chcc' stllisfaetorily with those of the elemental an ysis.

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7 phonites) of monoalkylen'e and upolyalky' lene' glyco' is and correspondstothc general form a:

in which R is an allten lradical and n is an integer equal to from 1 to 10 or higher, but preferably to from 1 to 4. A large number of these ycol esters have been prefiared, aswillbeseenfromTabesLIIlandIV. 'ltisbe eved, however, that the following Examples 7 and 8 will'suillce to illustrate the preparation of'these new compounds.

A. H. wisandR.D.Stayner. Aftereva rationitn motto of the resulting reaction mixture to a 3 the reaction mixture is cooled, diluted with e l e er filtered, and the solvent is then removed, under reduced rcssure. The iinal product is a tan'colored, water-solule liquid having the ormula Chi-O (OBsOHsOhK which, corresponding! is named dodecene diethylene glycol phosphonite. pon elemental analysis a 'Bhosphonis content of 9.2% is found, which agrees wi the calculated value of 9.6%.

Example 8 A mixture of 55.2 g. (0.2 mol) of n-tetradecene phoehenous acid and 0.2 of sodium h xide as a ca alyst is treated wise wdh ethylene e de with shaking, at a temperature 100 to 120' C. until the in weight after evaporation under reduced pressure about x ilpotrgficcgolingthereactionmiitture,theiinalproduct K OtsHsvi-O-(OHsOHsOhH i. e., tetradeeene hexaethylene glycol phosphonite. The elemental anal of this product indicated :uph hot-us coolant of 5.8 which agreed with the cal a value 0 6 visit othercatalysts ableofincreasingthereaction mi d oi-the reactions o i vas'iotss alkylene oxides and ailtcne httlsisphonous acids msy mm t hetemm in reaction varyln in tl ta afor ementioned application of A. H. Lewis and R.D.Sta Exam lesoftheeecatalystsare: nickel sulfate, pligahorie aclfi, boron tsifluorlda alky l sulfate, etc

'i'he slltene hosphonousacidsprodueedbythemethodofmy inveittioncanbeusedfortheptetantionot esters of various alcohols, e. ethyl alcoho him alcohol, benzyl alcohol, etc. likewise, Various and inoiiggnic salts of alkene may be P p Y mains M W n All of these esters and saltsfossesssurface-activi ,which fact renders them useful or a variety of one. Particularly interesting in this respect are the i metal salts of alltene Fhosphonous acid. I have prepared monosedium saltse severalslkenep ousacidsbythe foliowin proceduretAreaction by rcnc ng phosphorus trichl nn olefin, e. g. n l, in conditions set forth in Bxamp is slowly poured with stirring into 1 liter of wabenice being added at frequent intervals to maintain the temperature between 70 and 80' C. After cooling, the mixlure is extracted with petroleum ether, and the petroleum ether iraction treated with a 23% solution of sodium hydroxidc to yield a monosodiusn salt of an alkenephoephonous acid. This salt dissolves readily in water, is gartly soluble in strong alkaline solution, but is lc in petroleum ether. As will be shown de,aeeticanh the insolu to I later on in 35 otherwise'identi this specification, this type of salt is characterized by good wetting, detergent and foam-forming roperties, which vary in accordance with the particular al ene phosphonous acid employed. As ointed out at the outset of this description, alkene phosp onous acids and their derivatives containing a combination of hydrophobic organic and hydrophiiic morgrnic groups are characterized by surface-activity mamfcsted by detergency, emulsifying power, wetting power, foaming tendency, and the like.

Since alkene phosphonous acids and their derivatives such as salts,'esters, alittglene glycol and polyalkylene glycol esters, as well as e previouslydescribed derivatives of the intermediate phosphorates and phosphorites, are all characterized by various degrees of surface-activity, they are desirable as constituents for a number of useful compositions, for .instance, detergents, emulsifiers, suds boosters, wetting agents, and, the like. In view of the surface-active tendencies of the derivatives of alltene phosphonous acids, I carried out a number of tests to oornpare their surface-active properties, and particularlythe surface-active properties of the derivatives of n-dodecene, n-tetradeeene, n-hexadecene, and'n octadecene phosphonous acids with those of two well-known commercial surface-active agents: the anionic sodium alkyl benzene sulfonate in which the alkyl group is a polypropylene radicai containing from 12 to 15 carbon atoms, and the non iomc octyl henyl non lglycol ether. The results of these tests are ta ulated in e following Tables I, II, III and IV. Wetting activi values shown in Tables I and llhave been determined the so-called "canvas-square method which measures the number of seconds required for one square inch sample of standard #6 canvas to sink to the bottom when placed on thesurface of 200 ml. of a solutton to be tested in e250 ml. beaker.

'rsnu L-WI'ITING 'ao'rrvrrY or nnarva-rrvns 0F snxaun rnosrnonons some Number 0! O atoms in the I Aikene Portion. of the (Zlorsspous-id Add On on l. il

' E/H lioneeodlnm salt 3- I as s oNs Dlsthyleneglyool ester t 7 is. o 25.1 Ietraethy ycolester" so i 40.8 77. i Kesaethy yoolester 326 69.2 Oetaethylen yeolester 02.2 90.3 lodlum "Po ypro lens (Orr-Cu) bensene" luliona e. l Ogtyl Phenyl Nqnyl Glycol ne 1.1

I Concentration 0.9%. Wetting Times in seconds.

TLBLI Ila-FITTING ACTIVITY 0! DERIVATIVES 01 r ALKANE PHOSPHOBI'IES Oomponndwcneentntion 9.5%) .Sooonds nae: incessant s bonito h an. 46.1

sostniit tgeietb w l'fiogw sg l as es hos sa am lens oua oet ipa mluyaiu'isir 7.1

It is noted from the results of the wetting tests that diethyleneglycol ester of n-dodecene phosphonous acids is about as a wetting. agent (when used in a con-. ccntration o 0.5%,) as the octylphcnylnonylglycol ether and the um polypropylene benzene" sulfonate containing from 12 tolS carbon atoms in the pol ropyl ene chain when used in a concentration of 0.5

Detergency determinations were made on soiled cotton cloth in swordance with the standard iaunderomctcr pro tile Chemists and Colorists, 1944, p. 149). The rcsultin dcterpcncy data are given in terms of a,Soap Index which term is used-to designate a ratio of the percenta e of soil removal by the compound being tested to the percen ofsoil removalsecured with pure fatty acid s vo at'th'e same concentration and under test conditions.

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It is noted from Table III that the monosodium salts of alkene phosphonous acids containing from 14 to 18 carbon atoms in the alkenlyl radical and the alkylene glycol and polyakylene glyco esters of the same acids, w en employed as detergents for cotton cloth, compare favorably with the conventional commercial detergents such as lsodiulm '1 lypropylene benzene sulfouate and sodium aury su ate.

Foaming characteristics of the various derivatives of alkene phosphonous acids were determined for 0.4% soluuons threof in water by the Ross-Miles method described in "Oil and Soap for May 1941, pages 99-102. The results of these determinations are tabulated in Table IV. In this table the values are hfiven in millimeters and measure the height of foam w ch forms when 200 cc. of solution are allowed to fall in a fine stream through a distance of 90 cm.

TABLE IV.FOAHING CHARACTERISTICS OF DERIVA- 'IIVEB OF ALIEN! PEOBPHONOUB ACIDS Since it is generally held that only the values of 50 mm. or less are indicative of poor f the resul mistakably show the advantages whi can be secured with derivatives of alltene phosphonous acids in compositions where good foaming is desired. Derivatives of tetradeccne phosphonous acid are 1y effective as toam agents.

Tests were made to prepare stable 50-50 emulsions of xylene and water by using 2.596 of diethyleneglycol and tetraethyleneglycol esters of hexadecene and octadecene pbosphonous acids. The results were highly satisfactory and tn all four cases good lene-water emulsions were formed which remained stab c after twen -four hours.

In addition to the applicability of deriva of alkene phosphonous acids in different compositions as surfaceactive agents, such as detergents, wetting agents, suds boosters and emulsifiers, these acids and their corresponding phosphorite and phosphorate intermediates described heremabove, can be con to a number of derivatives suitable for the manufacture of oil additives, insecticides, gfillltlilcidfl, plasticizers and various other useful com- 17081 cm.

In concluding the above description, I wish it to be understood that the aforegiven mation and examples aremerslyillustrativeotthe tion,andthatsny modification of or variation therefrom in conformity with the spirit of the invention is to be included within the sctipgl o gthe following claims.

1. A process for preparing alltene phosphonous acids which comprises reacting at a temperature from about 0 to about 150' C., an olefin, phosphorous lilChi O'i'lde and acetic anhg'ndride, the mol ratio of phosphorus trichloride to the ole being at least about 2: 1, and hydrolyzmg and dehydrating the reaction roduct mixture.

2. A process as defined in c aim 1, wherein said hydrolysis and dehydration are eflected at a temperature from about 50' to about 150' C.

3. A rocess as defined in claim 1, wherein the react on of the o efln, phosphorus trichloride and acetic anhydride is efiected at a temperature from about room temperature to about C. and said hydrolysis and dehydration are effected at a temperature from about 50' to about C.

4. A process for preparing alkene phosphonous acids which comprises reacting at least 2 mols of phosphorus trichloride and l to 4 mo s of acetic anhydride with 1 mol of olefin at a temperature from about 0' to about 150 C. while bubbling through the mixture of the reactants an amount of oxygen in excess of the amount of the olefin present in the mixture, and subsequently hydrolyzing and dehydrating the reaction product mixture at a temperature from about 50 to about 150' C. I

.5. A process for preparing allrene phosphonous acids which comprises reacting at least 2 mols of phosphorus trichloride and l to 4 mols of acetic anhydride with 1 mol of an olefin containing from 8 to 20 carbon atoms in the molecule at a temperature from about 0' to about 150' C., and subsequently hydrolyzing and dehydrating the reaction product mixture at a temperature from about 50 to about 150 C.

6. A process as defined in claim 5, wherein said olefin is a polypropylene containing from 9 to 18 carbon atoms in e molecule.

7. In the process for preparing alkene phosphonous acids. the step of preparing an alkane-substituted intermediate containing two hosphorus atoms per molecule and convertible to said so ds b subsequent hydrolysis and dehydration. said step compris ng reacting an olefin, phosphorus trichloride and acetic anhydride at temperatures from about 0' C. to about 150' C., the mol ratio of phosphorus trichloride to the olefin being at least about 2:1.

8. Eil'ecting the process step defined in claim 7 in the presence of an excess of oxygen over the molar amount of olefiniresent in the reaction mixture.

9. process for preparing Cir-Cu alkcne phosphonous acids having the carbon-to-carbon double bond in the position a,# to the phosphorus atom. which comprises reacting a l-olefin. phosphorus trichloride and acetic anhydride at a temperature from about 0 to about 150 C., the mol ratio of phosphorus trichloride to the olefin being at least about 2:1, and subsequently hydrolyzing and dehydrating the reaction product mixture at a temperature from about 50 to about 150' C.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,268,157 Marvel Dec. 30, 1941 2,370,903 Hirachmann Mar. 6, 1945 2,374,807 Dickey May 1, 1945 2,381,071 McNally Aug. 7, 1945 2,425,766 Toy Aug. 19, 1947 2,492,994 Harman et al. Jan. 3, 1950 Willstatter Ber. Dent. Chem. 1944 2801-2814, v01 41, pp

Komla ff, ho Co Pi -127, E8 and iss Wands (1950 

7. IN THE PROCESS FOR PREPARING ALKENE PHOSPHONOUS ACIDS, THE STEP OF PREPARING AN ALKANE-SUBSTITUTED INTERMEDIATE CONTAINING TWO PHOSPHORUS ATOMS PER MOLECULE AND CONVERTIBLE TO SAID ACIDS BY SUBSQUENT HYDROLYSIS AND DEHYDRATION, SAID STEP COMPRISING REACTING AN OLEFIN, PHOSPHORUS TRICHLORIDE AND ACETIC ANHYDRIDE AT TEMPERATURES FROM ABOUT 0* C. TO ABOUT 150* C., THE MOL RATIO OF PHOSPHROUS TRICHLORIDE TO THE OLEFIN BEING AT LEAST ABOUT 2:1. 